CN101562359B

CN101562359B - High-conversion efficiency circularly polarized rectenna

Info

Publication number: CN101562359B
Application number: CN2009100520363A
Authority: CN
Inventors: 杨雪霞; 高艳艳; 周建永
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2009-05-26
Filing date: 2009-05-26
Publication date: 2011-11-23
Anticipated expiration: 2029-05-26
Also published as: CN101562359A

Abstract

The invention relates to a high-conversion efficiency circularly polarized rectenna, which comprises a microstrip receiving antenna and a microstrip rectifying circuit, wherein the microstrip receiving antenna and the microstrip rectifying circuit are printed on two layers of medium dielectric slabs overlapped up and down to form a structure of three metal layers and two medium layers, namely, a top layer of a square metal patch forming the microstrip receiving antenna, an intermediate layer which is a metal patch etched with a cross recess and arranged between the two layers of dielectric slabs and forms a grounding plate, and a bottom layer which is a microstrip feeder line and a microstrip rectifying circuit which are formed by metal patches. The high-conversion efficiency circularly polarized rectenna has the characteristics of simple structure, small cross section and low price, has high radio frequency energy to direct current conversion rate, and can effectively solve the power supply problem in applications such as wireless sensor network and radio frequency identification to eliminate the limitation of a battery.

Description

The circular polarization RECTIFYING ANTENNA of high conversion efficiency

Technical field

The present invention relates to the reception and the conversion equipment of a kind of microwave energy in the wireless energy transfer field, promptly RECTIFYING ANTENNA relates in particular to a kind of plane printing RECTIFYING ANTENNA, is used for microwave energy is received and convert to direct current.

Background technology

Microwave energy transfer (MPT:Microwave Power Transmission) system utilizes the little advantage of microwave loss in air, by free space microwave energy directly is transferred to receiving terminal from transmitting terminal, obtain direct current energy through rectification, realize the remote-wireless transmission of energy.The doctor of the Ni Gula tesla of the U.S. in 1899 (Nikola Tesla) proposes microwave delivery of energy notion the earliest.Nineteen fifties, western countries such as the U.S. begin to carry out the MPT Study on Technology, and being mainly used in for the solar power satellite plan that solves energy crisis, for the HAA of near space operation provides lasting energy, is remote hillman power supply or the like.Because MPT entire system conversion efficiency is not high, adds factors such as environment, bio-safety, the high-power applications of MPT technology also is in conceptual phase.

Since the 1990s, the research of micro-system has obtained fast development, and one of bottleneck technology that restricts the micro-system development and move towards practicability is the energy supply problem.At present, the metallic conduit energy supply or the heat radiation of various sizes will be used in thermal power plant, nuclear power station, chemical plant etc., and the safe handling of pipeline needs regularly to detect, because its space is little, pipeline is long, and turns round more, people select for use pipe robot to finish.The Micro-Robot volume is little, in light weight, thereby has limited battery life, if power with lead, has then limited the degree of freedom of its work.The MPT technology can remedy these shortcomings just, can provide convenient, stable, long-term electric energy to micro-systems such as pipe robots.

At present, constantly to miniaturization and portable development, the MPT technology shows tempting prospect in the low power applications field to electronic equipment.Radio-frequency (RF) identification (RFID:Radio Frequency IDentification), transponder, wireless senser, remote sensing, and other mobile wireless electronic equipment is the emerging application of wireless delivery of energy, generally in several meters even number cm range, these electronic equipments generally need have any operating time and extremely grow the function of stand-by time the power transfer of low power electronic device distance.The MPT technology can satisfy these requirements, and does not have energy life problems, becomes the best mode of the low power electronic device energy.The planographic RECTIFYING ANTENNA is easy to electronic equipment integrated and conformal, and along with the miniaturized electric subset develops to the practicability direction rapidly, wireless delivery of energy technology causes the very big interest of people.

RECTIFYING ANTENNA will obtain firing frequency-direct current conversion efficiency, at first requires reception antenna to provide sufficiently high incident power for diode, and the energy that causes for fear of electromagnetic wave transmitting-receiving polarization mismatch interrupts, and RECTIFYING ANTENNA requires circular polarization work.So need reception antenna to have high-gain, circular polarization, performance easy of integration.The printed dipole a little higher than paster antenna that gains, but be not easy to realize circular polarization, and the two water chestnuts rings of printing can work in circular polarization, but need add reflecting plate improves gain.

Here the plane high conversion efficiency circular polarization RECTIFYING ANTENNA of Ti Chuing has little, easy of integration, easy conformal, the advantage that do not need dual-mode antenna polarization to aim at of section.

Summary of the invention

The objective of the invention is to defective, a kind of circular polarization RECTIFYING ANTENNA of high conversion efficiency is provided, can solve effectively as the energy supply problem in the application such as radio sensing network, RFID, to break away from the constraint of battery at the prior art existence.This RECTIFYING ANTENNA not only has higher radio frequency to direct current conversion efficiency, simple in structure, easy to process, and is easy to the group battle array, is suitable for large-scale application.

For achieving the above object, the present invention adopts following technical proposals.

A kind of circular polarization RECTIFYING ANTENNA of high conversion efficiency comprises Microstrip Receiving Antenna and little band rectification circuit.It is characterized in that described Microstrip Receiving Antenna and little band rectification circuit are printed on the stacked up and down two layer medium plate, constitute three-layer metal layer and two layer medium layer structure: top layer is the square metal paster, constitute described Microstrip Receiving Antenna, intermediate layer between the two layer medium plate is that etching has the cross recessed metal patch, constitute ground plate, what bottom was that metal patch constitutes is microstrip feed line and little band rectification circuit.

Above-mentioned cross recess be positioned at described square metal paster under; Described microstrip feed line is positioned under the described cross recessed and is parallel to a diagonal of described square metal paster, and microstrip feed line links to each other with the input microstrip line of rectification circuit; The structure of described little band rectification circuit is: the little band minor matters of input T type connect the little band minor matters of output T type, rectifier diode ground connection of input T type little band minor matters and output T type little band minor matters junction, the little band minor matters of output T type output is ground connection after the electric capacity of parallel connection and DC load.

Above-mentioned microstrip feed line is identical with the input micro belt line width of little band rectification circuit, realizes that nature is excessive.

The present invention is printed on the circular polarization RECTIFYING ANTENNA on the two-layered medium plate.The two water chestnut ring of coplanar wave guide feedback circular polarization RECTIFYING ANTENNA has the rectification efficiency near 80% at present, but need add reflecting plate in order to improve antenna gain, thereby has increased longitudinal size; The square circular polarization RECTIFYING ANTENNA of feed microstrip line corner cut is simple in structure, and section is little, but has only the rectification efficiency about 50%.The present invention adopts following measure, is obtaining under the situation of high rectification efficiency, makes RECTIFYING ANTENNA have low section, easy of integration, easy conformal, advantage of simple structure.

1. the intermediate metal layer of two-layered medium plate is as the common ground plate of reception antenna and rectification circuit;

2. the size of length, position and the square patch in cross recess coupling slit is determined the operating frequency and the circular polarization characteristics of reception antenna;

3. the feeding classification of antenna adopts feed microstrip line, and realizes by the slit coupling.

The present invention guarantees that diode obtains enough radio-frequency (RF) energy, so that rectification circuit has high conversion efficiency by the high-gain of the firm and hard existing microstrip antenna of two-layered medium and the working band of broad.The microstrip feed line of antenna is identical with the width of rectification circuit input end microstrip line, is designed to 50 ohm.Characteristics simple in structure, that section is little, cost is low that this RECTIFYING ANTENNA has, and have higher radio-frequency (RF) energy to galvanic conversion efficiency, can effectively solve as the energy supply problem in the application such as radio sensing network, radio-frequency (RF) identification, to break away from the constraint of battery.

The present invention compared with prior art has following conspicuous outstanding substantive distinguishing features and remarkable advantage:

1. Microstrip Receiving Antenna is a feed microstrip line cross recess coupling two-layered medium micro-strip paster antenna, realizes that with the microstrip line rectification circuit nature is excessive.

2. circular polarization work realizes by cross recess and square patch, has only a distributing point, only need connect a rectification circuit; And common circular polarized antenna has two distributing points, need connect two rectification circuits.

3. reception antenna and rectification circuit place the different medium layer respectively, significantly reduce the influence of rectification circuit to reception antenna.

4. the double-decker microstrip antenna has bigger standing-wave ratio bandwidth and higher gain than single layer structure.

5. this RECTIFYING ANTENNA section is little, and is easily conformal, easy of integration.

6. this RECTIFYING ANTENNA has circular polarization characteristics, can receive the microwave energy of any polarization.

7. has the high conversion efficiency more than 75%.

8. its feed microstrip line mode makes RECTIFYING ANTENNA be easy to the group battle array, is applied to large-power occasions.

Description of drawings

Fig. 1 is a RECTIFYING ANTENNA structure top view;

Fig. 2 is the RECTIFYING ANTENNA end view;

Fig. 3 is a feed microstrip line slit coupling circular polarized antenna structural representation;

Fig. 4 is the rectification circuit structural representation.

Embodiment

Details are as follows in conjunction with the accompanying drawings for a preferred embodiment of the present invention: as depicted in figs. 1 and 2, this RECTIFYING ANTENNA comprises microstrip antenna 1 and little band rectification circuit 2.Described Microstrip Receiving Antenna 1 and little band rectification circuit 2 are printed on the stacked up and down two layer medium plate, constitute three-layer metal layer and two layer medium layer structure: top layer is the square metal paster, constitute described Microstrip Receiving Antenna 1, intermediate layer between the two layer medium plate is the metal patch that etching has cross recess 3, constitute ground plate 11, what bottom was that metal patch constitutes is microstrip feed line 4 and rectification circuit 2.Microstrip feed line 4 width are identical with the input micro belt line width of little band rectification circuit 2, realize the nature transition.Work in C-band.

The reception antenna unit comprises Microstrip Receiving Antenna 1, cross recess coupling slit 3, microstrip feed line 4, two layer medium plate 10 and ground plate 11, as shown in Figure 3.The central point of described Microstrip Receiving Antenna 1 is vertical with dielectric-slab 10 with the line of the central point that cross recess intersects, and cross recess size, microstrip feed line are determined the operating frequency and the circular polarization characteristics of reception antenna unit with respect to the effective length of cross recessed extension elongation.Microstrip Receiving Antenna 1 receives electromagnetic wave energy, by cross recess 3 electromagnetic wave energy is coupled to microstrip feed line 4.

Little band rectification circuit 2 is made up of the little band minor matters 5 of input T type, diode 6, the little band minor matters 7 of output T type, electric capacity 8 and DC load 9, as shown in Figure 4.The input of described input T type minor matters 5 directly is connected with microstrip feed line 4; The positive pole of diode is welded between the little band

minor matters

5,7 of two T types, minus earth; One face down bonding of electric capacity 8 and DC load 9 is connected on the output of the little band minor matters 7 of output T type, opposite side ground connection.Enter diode 6 from the electromagnetic wave energy of microstrip feed line 4 by input T type minor matters 5 and carry out rectification, dc energy and a spot of microwave energy are through output T type minor matters 7, arrive electric capacity 8 and DC load 9, at this moment direct current energy is collected by DC load 9, electromagnetic first-harmonic and high order harmonic component are reflected back toward diode 6, rectification once more.

This RECTIFYING ANTENNA has 75% the radio frequency conversion efficiency to direct current at C-band.

Claims

1. the circular polarization RECTIFYING ANTENNA of a high conversion efficiency, comprise Microstrip Receiving Antenna (1) and little band rectification circuit (2), it is characterized in that described Microstrip Receiving Antenna (1) and little band rectification circuit (2) are printed on the stacked up and down two layer medium plate, constitute three-layer metal layer and two layer medium layer structure: top layer is the square metal paster, constitute described Microstrip Receiving Antenna (1), intermediate layer between the two layer medium plate is the metal patch that etching has cross recess (3), constitute ground plate (11), what bottom was that metal patch constitutes is microstrip feed line (4) and little band rectification circuit (2);

Described cross recess (3) is positioned under the described square metal paster; Described microstrip feed line (4) be positioned at described cross recess (3) under and be parallel to a diagonal of described square metal paster, microstrip feed line (4) links to each other with the input microstrip line of little band rectification circuit (2); The structure of described little band rectification circuit (2) is: the input T little band minor matters of type (5) connect the output T little band minor matters of type (7), input T little band minor matters of type (5) and the output T little band minor matters of type (7) rectifier diodes in junction (6) ground connection, the output T little band minor matters of type (7) output is ground connection after the electric capacity (8) of parallel connection and DC load (9).

2. high conversion efficiency circular polarization RECTIFYING ANTENNA according to claim 1 is characterized in that described microstrip feed line (4) is identical with the input micro belt line width of little band rectification circuit (2), realizes the nature transition.